T-Mobile today began rolling out a LTE Advanced version of Voice over LTE (VoLTE) in the Seattle area for LG G Flex and Samsung Galaxy Light and Note 3 customers, with plans to roll it out to more T-Mobile customers throughout the coming year. Here's more info:

VoLTE is the next major advancement in LTE and essentially brings both data and voice onto the same radio layer, as it should be. Customer benefits include faster call setup times (almost twice as fast as a non-VoLTE call setup) and the ability to enjoy lightning fast LTE data speeds while on a call. HD Voice service is also included with VoLTE.

To experience VoLTE on T-Mobile, existing LG G Flex and Galaxy Note 3 and Galaxy Light customers in Seattle just need to go into device "Settings," "General" and "About device" to get the latest Software Update.